The invention pertains to a screw compressor with a rotor housing in which two screw rotors that mesh with one another with screw-shaped ribs and grooves are rotatably held with parallel axes, and with a cooling housing that surrounds the rotor housing at a distance, forming a cooling chamber together with the rotor housing, said cooling housing having an inlet opening and an outlet opening for a coolant flowing through the cooling chamber.
A screw compressor of this type is known from DE 201 10 360.5 U1 as part of a two-stage screw compressor for example.
The invention has particular advantages when applied to a screw compressor that compresses a gaseous medium such as air to very high pressures in the range of 30 to 50 bar, in particular about 40 bar, and in which the application involves the high pressure stage of a two or three stage compressor system in particular. Consequent with the compression to very high pressures is significant heating of the gaseous medium so that especially effective cooling is desired.
It is therefore an object of the invention to design a screw compressor of the type indicated that has an especially effective cooling system. Another object is to construct the screw compressor such that the emptying and filling of the cooling chamber with coolant is especially simple.
Through the invention, the coolant in the cooling chamber flows around the external surface of the rotor housing over nearly 360° of its periphery. Furthermore, the coolant sharply reverses its direction when it flows into the cooling chamber and again prior to flowing out; this redirection occurs at the separating wall that connects the rotor housing to the cooling jacket. What was discovered is that in this way, a very intensive cooling effect is accomplished, in particular near the separating wall, which acts like a cooling rib.